Tensions between Germany and Britain over how to handle the crisis in the eurozone deepened after allies of the German chancellor, Angela Merkel, claimed she would not allow the UK to "get away" with its refusal to back a European financial transactions tax.

Speaking before a meeting between Merkel and David Cameron on Friday, the parliamentary leader of her Christian Democratic Union said: "Britain had a responsibility to make Europe a success."

Volker Kauder, at the CDU conference in Leipzig, said: "I can understand that the British don't want that [a transactions tax] when they generate almost 30% of their gross domestic product from financial-market business in the City of London. Only going after their own benefit and refusing to contribute is not the message we're letting the British get away with."

The transactions tax on shares and other City exchanges – otherwise known as the Tobin tax or Robin Hood tax – has been supported by the French president, Nicolas Sarkozy, and leading UK charities. But Britain has resisted its implementation without it being copied by the US and other leading economies.

Asked about Kauder's remarks, the prime minister's spokesman said: "There is clearly going to be a debate about Europe and the shape of Europe over the coming weeks, months and years. What we would say is that the crisis means that we should focus on the economics.

"It is very clear that countries need credible plans to deal with their debts and deficits and we shouldn't be deflected from dealing with the structural problems in European countries."

In remarks that will further inflame Tory Eurosceptics, Kauder also claimed that Europe was now embracing Merkel's solutions to the crisis by focusing on tougher fiscal discipline for indebted countries. "Now all of a sudden, Europe is speaking German," he said. "Not as a language, but in its acceptance of the instruments for which Angela Merkel has fought so hard, and with success in the end."

The crisis in the eurozone is prompting Germany to draw up possibly far-reaching plans for change to EU treaties that would force Cameron to demand concessions in return. This process could in turn expose tensions between Conservatives and Liberal Democrats over Europe.

In his annual foreign policy speech at the Lord Mayor of London's banquet on Monday, Cameron said the crisis provided an opportunity for the EU to rethink its purpose and rules and to refashion it as a looser union.

On Tuesday the deputy prime minister, Nick Clegg, urged Europe's leaders not to disappear into a "windowless room" to debate institutional changes. The idea that one could simply get on the Eurostar, go over to Brussels and come back with a bagload of powers simply is not feasible, Clegg said. No 10 said Clegg and Cameron were agreed on making Europe focus on "the issues that matter".

European Commission data releasedon Tuesday showed economic growth between July and September of only 0.2% in both the 17 eurozone nations and across the 27 EU nations. The bulk of the growth came in Germany and France. Only Greece, Portugal and Cyprus grew more slowly than Britain over the last year. The eurozone has grown by 1.4% over the last year, compared with just 0.5% in the UK.

The figures suggest UK youth unemployment will go over the politically sensitive 1 million mark when figures are published on Wednesday. The business secretary, Vince Cable, will try to quell the political storm by announcing an incentive of up to £1,500 per person for companies with 50 employees or fewer to take on up to 20,000 apprentices aged 16-24. Labour claims youth unemployment has risen by 93 % since the general election.

Ministers, still struggling to assemble a coherent growth package before the autumn statement on 29 November, fear that whatever measures they announce around labour market reform will seem inadequate alongside the collapse in consumer demand.

Ed Balls, the shadow chancellor, said: "Instead of wrongly blaming events abroad for his own mistakes at home, David Cameron needs to realise that our economy has flatlined for more than a year – well before the recent eurozone crisis."

Signs grew that the European sovereign debt crisis is spreading across Europe, with France, Spain and even Belgium seeing bond yields rising significantly. Italian 10-year bonds moved back over the critical 7 % level. Bond yields are the interest rate countries have to pay to fund their debt.